Claudia Borrero

Oocyte donation and gamete intrafallopian transfer in premature ovarian failure

Gamete intrafallopian transfer (GIFT) was performed in eight patients with premature ovarian failure (POF), using donated oocytes. The steroid replacement protocol consisted of the administration of increasing dosages of 17β-estradiol (E2) and progesterone (P). Hormonal replacement was maintained until day 100 of gestation. All patients underwent an evaluation cycle in which serum levels of E2 and P were monitored and an endometrial biopsy was performed on day 21 or 22. All cases of GIFT were performed between days 12 and 15. Six clinical pregnancies were achieved in eight cycles (75% success rate). Three patients delivered and three are in their second or third trimester. No ectopics or miscarriages occurred. These results offer a promising approach for the establishment of fertility in agonadal patients.

Tubal embryo transfer as a treatment for infertility due to male factor

Transvaginal follicular aspiration (TVA) with ultrasonically guided needles allows the transfer of in vitro generated embryos to the fallopian tubes (TET), performing only one surgical procedure in the process. Up to now, this approach has been used to treat 16 couples with infertility due to severe male factor. Follicular development was induced with a combination of clomiphene citrate and human menopausal gonadotropin (hMG) or follicle-stimulating hormone and hMG. Follicles were aspirated by TVA 36 hours after an injection of human chorionic gonadotropin 10,000 IU intramuscularly. A total of 169 oocytes were recovered (10.5 +/- 6.9 X +/- SD) from the 16 patients. There was failure of fertilization in 6 cases. In the remaining 10, a TET was performed 44 to 50 hours after TVA, utilizing embryos at the pronuclear stage. Six pregnancies resulted from the 10 transfers. This technique combines the advantages of proof of fertilization with a more adequate tubal embryo development and entrance to the uterine cavity that may determine and increase chance of implantation.

Luteinizing hormone-releasing hormone analogs: female contraception.

Exploration of the potential uses of luteinizing hormone-releasing hormone (LHRH) analogs in contraception has involved inhibition of ovulation of implantation and luteolysis. LHRH analogs when given chronically have the paradoxical effect of down-regulating or desensitizing LHRH receptors in the pituitary raising LH and FSH levels and producing a hypogonadal state. Studies in rhesus monkeys have documented that LHRH given in the early follicular phase block follicular growth and delay ovulation. In women the LHRH analog 4f-Antag given sc also prolonged follicular phase but had no effect on luteal phase. Several LHRH analogs have effectively inhibited ovulation in women: Buserelin Naferelin Leuprolide ad D-TRP. While ovulation is consistently blocked some women experience amenorrhea some oligomenorrhea and some menstruation-like bleeding. Estrogen levels resemble follicular phase levels but the degree of gonadotropin suppression varied from hypoestrogenic conditions of vasomotor symptoms and atrophic vagina to a potential for endometrial hyperplasia. Combined treatments with LHRH analogs and progestins norethisterone or medroxyprogesterone acetate have been tested to induce withdrawal bleeding and prevent endometrial build-up. Another problem with these experimental ovulation-inhibiting treatments is that the intranasal spray route produced variable absorption but the daily injections are not practical. Long-acting implants or injections are being formulated. Conflicting results have appeared in studies on the possible luteolytic effect of LHRH analogs. Work in rhesus monkeys and in women suggests that a narrow window of time is required to get a luteolytic effect. Multiple doses or chronic administration of LHRH analogs will terminate early pregnancy in small animals and nonhuman primates. No effect on implantation has been reported in the few small trials in women to date.